Semiconductor workpieces are often implanted with dopant species to create a desired conductivity. Plasma implantation is an effective method of doping or otherwise modifying surfaces of a semiconductor device. For example, plasma implantation may be effective in doping the vertical surfaces, also referred to as sidewalls.
Many types of emerging semiconductor device structures utilize sidewall modification, including FinFETs, 3D NAND gates, CIS and power devices. In certain embodiments, it may be desirable to modify the sidewalls with low, or even very low, concentrations of dopants or other species.
However, plasma chambers are typically better suited to perform implants with higher dopant concentrations. Precision and repeatability at very low doses may be problematic.
Therefore, a method that allows a precise amount of dopant to be deposited and subsequently implanted into a workpiece, would be beneficial.